1. Field of the Invention
The present invention relates to a walk-type lawn mower including a lawn mowing unit mounted integrally thereto in front of a machine body and a grass catcher for storing lawn chips arranged in front of the lawn mowing unit and being configured to be operated as an operator walks behind the machine body, and a catcher frame apparatus.
2. Description of the Related Art
The walk-type lawn mower in the above form is generally classified into two types depending on the mounting structure of the lawn mowing unit to the machine body. One is a type having a lawn mowing unit U′ provided integrally in front of a machine body 1′ and a grass catcher G′ detachably attached to a frame of the lawn mowing unit U′ as shown in FIG. 10, which is referred to as “machine-body integrated type”, hereinafter (see FIG. 4 in Japanese Patent No. 3884055). The other one is a type having a lawn mowing unit U″ mounted in front of a machine body 1″ via a unit frame 91 in a state of being towed and a grass catcher G″ detachably mounted to the unit frame 91 as shown in FIG. 11, which is referred to as “tow type” hereinafter (see JP-B-5-39564).
The lawn mower of the “machine-body integrated type” has such advantages that it is composed of a small number of components and hence is simple in structure, and is maintenance-friendly. However, it has such a drawback that the weight of lawn chips L stored in the grass catcher G′ increases in proportion to the amount of mowing operation and the weight is applied to a front roller 4′ of the lawn mowing unit U′ directly and causes the front roller 4′ to weigh down. On the other hand, the mowing height of the lawn achieved by the lawn mowing unit U′ is determined by the height of the front roller 4′ of the lawn mowing unit U′. Therefore, there arises a problem such that when the weight of the lawn chips L stored in the grass catcher G′ increases in association of the progress of the mowing operation, the amount of weighing down of the front roller 4′ of the lawn mowing unit U′ gradually increases, and hence the mowing height of the lawn is gradually lowered.
In the case of the lawn mower of the “tow type”, the machine body 1″ and the lawn mowing unit U″ are separated, and the weight of the lawn chips L stored in the grass catcher G″ is applied to a unit roller 92 mounted to the lower front of the unit frame 91 and is not applied to a front roller 4″, and hence the mowing height is little changed from the beginning to the end of the mowing operation. Furthermore, since the lawn mowing unit U″ is able to follow the direction of travel of the machine body 1″, the direction orthogonal thereto, and the inclination (undulation) of the lawn along the composite direction of these two directions, the mowing operation is easily carried out even on the inclined surface. However, since the number of components is significantly large, and the entire length of the lawn mower is long, a large force is required when the operator pushes down a handle to lift the lawn mowing unit U″ to change the direction of mowing during the mowing operation or to transfer the lawn mower and, simultaneously, since the lawn mowing unit U″ is brought into a state of being suspended by a chain 93 from the unit frame 91, the operator needs to push the handle down by a large amount correspondingly, which deteriorates the operability. In FIG. 10 and FIG. 11, reference numerals 2′ and 2″ designate reel cutters of the lawn mowing units U′ and U″, and reference numerals 9′ and 9″ designate driving drums.